Paris, she'll suck your batteries dry

$25 is ridiculous and it uses 3 AAA's, so direct driven LED and possibly no dropping resistor, plus the weight of 3 AAA's.

There is a chip that will drive a LED from an input source of 0.9V to 6V. When the source is above 0.9V it maintains a constant light so unlike the 3 AAA direct driven lights, it won't dim as the batteries wear. Below 0.9V, it starts to dim. It sucks every last bit of energy out of a battery.

It costs 80 cents and it comes with an inductor. I'm sure it'll be cheaper in bulk.

I have a LED torch that cost me $11. It uses such a similar chip but it has a hard anodised aluminum body to justify the cost and uses a single AAA battery. I haven't changed the battery in it for months. Attached to pivoting head on a goose neck with a clip, all purchased at a shit shop (dollar or pound stores in your local lingo), total cost $12.